The present invention generally relates to locks for overlapping parallel sliding members, such as sliding glass doors and windows, and more particularly to a hinge member having two leaf members, with the leaf members being pivotable between locked and unlocked positions.
U.S. Pat. No. 3,873,693 discloses a prior lock similar to the present invention for overlapping parallel sliding members, and the disclosure of said patent is incorporated herein as if fully set forth herein.
A significant drawback of the prior lock was its complex and expensive, yet non-intuitive and delicate, detent pin. The necessity of withdrawing the spring loaded pin prior to pivoting the leaves was not immediately apparent. Persons unfamiliar with the operation of the prior lock would typically force the lock open without first withdrawing the pin, thereby breaking the pin.
Thus, an object of this invention is to provide a simple inconspicuous element attached to one member of overlapping parallel sliding members, which may be positioned to permit free sliding of the overlapping members with respect to each other, and positioned in another position to obstruct or prevent movement of said overlapping sliding members with respect to each other.
A further object of this invention is to provide a hinge type member having one leaf thereof permanently secured to one of overlapping sliding members, and the second leaf thereof pivotal between locked and unlocked positions to permit sliding of said overlapping members in the unlocked position; and, when turned a 90 degree angle to the locked position, to abut the face of one of said overlapping members to prevent displacement there between; and, a resistance mechanism for lightly-resisting pivoting of said pivotal leaf member against displacement or rotation, the resistance mechanism being indestructible in normal operation without pre-manipulation of any portion of the lock prior to pivoting movement.
A still further object of this invention is to provide a device as described which will be simple and economical in construction and efficient and durable in use.